The construction diagram (shown below) is
based on the Album des pavillons nationaux et
des marques distinctives (National flags and distinctive markings) 2000
edition
[pay00] and is correct according to 'The National
Flag and Foreign States Flags (Amendment) Act' which established it and
which came into force on 20th May 1970. The relevant Article reads as
follows:

Description and Dimensions of the National Flag.

3. The National Flag is rectangular in shape, its width is half its length
and it consists of three equal horizontal rectangles and ends on the side of
the staff with a triangle of two equal sides, the length of the base of the
triangle is the width of the flag and the length of its vertical height is
one-third the length of the flag. The colours of the rectangles from top to
bottom are red, white and black respectively and the colour of the triangle
is green."

According to the construction details provided in the Album des pavillons nationaux et
des marques distinctives (National flags and distinctive markings) 2000
edition
[pay00] , the triangle reaches
with its top from hoist towards center double the width of one stripe (which in turn is 1/3 of the length, of course).
Željko Heimer, 21 Jan 2003

The protocol manual for the London 2012 Olympics
(Flags and Anthems Manual, London, 2012 [bib-lna.html])
provides recommendations for national flag designs. Each National Olympic
Committee was sent an image of their flag, including the PMS shades, by the
London Organising Committee of the Olympic Games (LOCOG) for their approval.
Once this was obtained, the LOCOG produced a 60 x 90 cm version of the flag for
further approval. So, while these specifications may not be the official,
government, version of each flag, they are certainly what the National Olympic
Committee believed their flag to be.

Image
by Paige Herring, taken from Flags of the World by William Crampton (1990)
[cra90i], 21 May 1998

The description of the Arms is given as follows:
'The arms are a secretary bird with a native shield on its breast; above it is a scroll with the motto, "Al Nadr Nila" (Victory is Ours), and beneath it is the name of the country.'
Sources: Flags and Arms across the World by Whitney Smith (1980) [smi80]
and Guide to the Flags of the World by Mauro Talocci (1982) [tal82].Paige Herring, 21 May 1998

Above is an image from
Wappenlexikon of the former Sudanese coat of arms used between 1956 and
1970. The main feature of the emblem is a rhinoceros enclosed by two
palm trees.Zoltan Horvath, 02 Aug 2010

Some years ago Jose Luis Cepero spent some time in Sudan. On TV he saw a flag that is white with the (current) national flag in canton.

Image by Željko Heimer, 24 Jan 2003

Since pre-1969
war ensign was in of the same pattern, I assume that Sudanese Navy used after 1969
is also a white ensign with the new national flag in the canton - but this needs
to be confirmed.Jaume Ollé, 06 Jan 2001